The occurrence of fungal infections has escalated significantly in recent years and is expected to continue to increase for the foreseeable future. Unfortunately, only a limited number of antifungal drugs are currently available for use. This is due in part to the lack of defined targets available for exploitation in the search for new antifungal agents. Thus, the ultimate aim of this proposal is to identify new targets for use in this capacity. The premise is that new targets might be identified by determining the subset of genes that are expressed solely during growth in the infected host. It is expected that corresponding gene products will be required for in vivo growth and/or infectivity and thereby, will be attractive target candidates. In this context, the primary aim of this Phase I proof of principle investigation will be to utilize differential display technology to determine whether differences in fungal gene expression can be detected during in vivo growth in an animal model system. Subsequent experiments will analyze the detected genes and determine their role in infectivity. During Phase II investigations it is expected that the design of appropriate assays and compound screens will lead to the development of novel antifungal agents. PROPOSED COMMERCIAL APPLICATION Successful identification of new antifungal targets could greatly aid in the development of safe and effective drugs for chemotherapeutic treatment of deep-seated mycosis.